Bearing



amh 13- 1193?. E. BENEDEK 2,3743% BEARING 5 Sheets-Sheet 1 Filed Nov. 4,1532 March W, WW, E. BENEDEK fl v BEARING Filed Nov. 4,. 1932 5Sheets-Sheet 2 7 March 1%, 1937. E I 2,@74,ZU2 v BEARING Filed Nov. 4,1952 5 Sheets-Sheet 3 E. BEN EDEK 2,@74,22

BEAR ING Filed Nov. 4, 1932 I 5 Sheets-Sheet 4 WWW Mm-ch H6, W37. E.BENEDEK I fi v BEARING Filed Nov. 4, 1932 5 Sheets-Sheet 5 Patented Mar.16, 1937 UNITED STATES PATENT OFFICE BEARING Elek Benedek, Mount Gilead,Ohio Application November 4, 1932, Serial No. 641,186

16 Claims. (Cl. 308-}202) This invention relates to bearings and moreparticularly to roller bearings of the type in which the length-diameterratio of the individual roller elements is large, the individualelements being herein termed needle rollers because of their elongatedshape.

In accordance with my invention hardened and ground needle rollers areassembled in such manner as to provide capillary clearance spaces 19between adjacent roller elements so as to permit the elements to rollindividually without rubbing against each other in metal-to-metalcontact 'or' engagement. Capillary spaces are provided by employingneedle rollers of such length-diameter 1.3 ratio that when assembledwith a small amount of circumferential clearance, adjacent needles andthe associated races will cooperate to define long narrow interspacesacting in the well known manner of capillary tubes to draw in fluidlubrio cant. -The capillary attraction provides, in a sense, forced feedlubrication preventing the needles from throwing the lubricant oif dueto centrifugal force. According to a further feature of the invention,the mechanical cage heretofore as often employed for maintaining rollingbearing elements in parallelism, is eliminated. The needle rollers of myinvention themselves cooperate with lubricant'in the capillary spacesfor maintaining the needle rollers parallel to each other :0 without theuse of a cage.

The needle rollers may be made by the centerless grinding method.

The needle roller bearing in accordance with my invention differsentirely in its function and 35 structure from the sliding andanti-friction bearings as heretofore known. In respect to its structure,and without reference to the length-diameter ratio of the individualelements and the circumferential clearance therebetween, it is similar4-0 to a cageless roller bearing. Between hardened and ground bearingsurfaces there is a plurality of elements with circular cross-sectioncalled the needle rollers. As distinguished from heretofore knownanti-friction rollers, the needle rollers 45 have a capillary diameterand their length is always many times greater than the length of thediameter of 'a needle. This length is, however, not arbitrary and it isthe purpose of this invention to provide needles with certain specificratio .50 between length and diameter so that the length does not exceedsuch a length which is able to maintain full lubrication at all timesbetween the needles sufficient to allow free individual rotation foreach needle which is carrying the load 55 at that instant. Needlesproportioned according to this invention are self-lubricating by thecapillary action of the capillary interspaces, formed by the needles andtheir coacting bearing members. Furthermore the specific length is sodetermined that the unlt pressure on the loaded or, better to say,working needles is great enough to force the working needles'to rollaround their individual axis while the needles on the unloaded side ofthe bearing are revolved about the axis of the bearing along with theworking needles due to the rotation of the working needles, therevolution of the assembly of needles being thereby at a speed whichisonly one-half of the speed of revolutions per minute of the rotatingbearing member. Thus, by forcing the working needles to rotate, the idleneedles will be driven and revolve as an asembly in unison with theworking needles with a speed equal to approximately onehalf of therevolutions of the rotating active hearing member.

The term active bearing member means a load transmitting rotatingbearing element. The term needle-cylindrical or quasi-cylindrical-meansan element which in combination with similar needles may form capillaryspaces. The term passive bearing member means a stationary bearingmember. Applicant knows that the application of full roller bearings andof sliding needles is not entirely new. Bearings of the full type areproposed in U. S. Patent No. 268,236. Bearings of the sliding needletype are proposed in U. S. Patent Reissue No. 18,080. a

In the latter patent, the needles are made so long as to normallyprevent by the friction between two needles the rolling about individualaxis of the individual needles. By the braking effect of the needles,said Letters Patent dis-' closes and proposes essentially a slidingneedle bearing with lubricant maintained in a closed 40 cylindricalspace by splash lubrication. According to the present invention Iprovide a bearing structure in which, during the operation of thebearing, one group of the needles is rolling under load with the drivingbearing member or race whereas the other group of needles is idle and isdriven bythe rolling needles. This operation of the needles is readilyunderstood when it is remembered that there is no cage in the bearingand that the needles must maintain the right working relation in a wholeby the assembly and self-adjustment. The total clearance according tothe size of the needle bushing diameter ranges about one to two needlesper bearing. Thus, there is some operative clearance between the needlesbut not too great to allow transverse disa angement of the individualneedles. In order to break up the friction between the individualneedles and allow them as perfect rotation as possible to roll with therespective bearing speed,

the length is cut short enough for that.

It is because of the novel assembly of rollers of high length-diameterratio with capillary clearance spaces between them that permits the"needles to roll that my bearing possesses novel and improved operatingcharacteristics and load carrying capacity and it is because of thisnovel assembly that it is distinguishable over the bearings of the priorart. My bearing combines two desirable characteristics heretofore onlypresent in distinct types of bearings; namely, capillary lubrication(plain or needle slide bearings), and anti-friction or rolling loadtransmission (conventional roller bearings). It can be adopted withgreat advantage to replace either of the above mentioned types ofbearings due to its great load-carrying capacity which exceeds ten timesthe capacity of bearings hitherto known, in a much smaller space.

The lubrication by the capillary forcein this design eliminates entirelyfriction between the needle rollers and provides a greater eificiencybearing than has been known previously. The capillary attraction bindsthe lubricant between the needles and maintains it in the peculiartriangular wedge-shaped form as an oil film. In reciprocating bearingswhere otherwise the lubrication is difficult and often impossible thistype of bearing is very well adaptable such as in crankshafts, cylinderwrist-pins, and the like.

Due to the formation of the effective oil field and oil film throughoutthe entire length of the needles, in combination with the rolling of theworking needles and the swimming of the idle 4O needles in the clearancespace of the unloaded side of the bearing, the friction coeificient isideal and figures to be 0.004 which is one-tenth only of the friction ina well-lubricated plain sliding hearing. The elimination of the cageallows the widest possible application of this bearing in single radial,multi-row-radial, single ring axial thrust or multi-ring axial thrustbearings. The dimensions of needle bearings are smaller than that of anyexisting bearings due to the greater load capacity of it. Theirapplication without cages saves space and weight.

More specific objects and advantages will appear from the followingdescription of several illustrations of present invention which form apart of this specification.

In the accompanying drawings:

Fig. 1 shows a bearing structure constructed according to the presentinvention in a sectional view, wherein the shaft and the outer bearingmember have plain bearing surfaces and the axial guiding of the needlesis accomplished by two parallel plates.

Fig. 2 is a bearing, similar to Fig. 1, except that the needles aremounted in recesses in the shaft and the outer race is plain.

Fig. 3 is similar to Fig. 1 except that the needles are packed withintervening capillary clearance in the outer race which has shoulders.

70 Fig. 4 shows a complete bearing with inner and outer races, mountedon a shaft.

Fig. 5 is similar to Fig. 4 except that it shows a double row completebearing.

Fig. 6 is similar to Fig. 5, except that it shows 75 a triple row needlebearing.

Fig. '1 is a vertical sectional view of Figs. 5 and 6. v

Fig. 8 is an end view of Fig. 9.

Fig. 9 is a central sectional view of a capillary tube containing fluidentrapped and kept therein by the capillary attraction.

Fig. 10 is an arbitrary transverse section of Fig. 9.

Fig. 11 is a diagram showing the capillary length of an oil column whichcan be maintained by the capillary force in the tube against thegravitational force, plotted against the diameter of the capillary tubeas abscissa, and the length as ordinata.

Fig. 12 is a needle constructed in accordance with present invention.

Fig. 13 is an end view of Fig. 12.

Fig. 14 is a complete needle bearing constructed in accordance withpresent invention.

Fig. 15 is a sectional view of Fig. 14, taken at the vertical meridianof the bearing.

Fig. 16 shows the application of a double row bearing mounted on thewrist pin of a large Diesel engine.

Fig. 17 is a perspective view of Fig. 16, with the outer bearing partsremoved.

Fig. 18 shows a portion of a capillary interspace formed by two needlesand the cooperative bearing parts, in, perspective engagement.

Fig. 19 shows a needle bearing of the reciproeating type.

Fig. 20 is a vertical section of Fig. 19.

Fig. 21 shows an open bearing as supporting the reciprocating crossheadof a high pressure pump, taken through the center line of the pistons.

Fig. 22 is a transverse section of Fig. 21.

Fig. 23 is an open bearing used in a high pressure rotary pump, takenthrough the center line of the pistons.

Fig. 24 is a transverse sectional view of Fig. 23.

Fig. 25 is a needle retainer used in Figs. 19, 20, 21 and 22.

Fig. 26 is a view of Fig. 27.

Fig. 2'7 shows a needle roller with slightly tapered form.

Fig. 28 is a side view of the. small end of the needle in Fig. 27.

Fig. 29 shows a complete bearing constructed with slightly taperedneedles.

Fig. 30 is a partial sectional view of Fig. 29.

Fig. 31 shows a double row tapered needle bearing.

Fig. 32 shows an inner race alone with capillary interspaces shown afterthe needles are removed.

Fig. 33 is a tapered capillary interspace constructed after needles andraces are removed.

Fig. 34 shows the application of tapered needles in supporting the rotorof a water turbine.

Fig. 35 is a sectional view of Fig. 34 taken in a plane above theneedles.

Fig. 36 is an enlarged portion of Fig. 34.

Fig. 37 is an enlarged portion of Fig. 35.

Fig. 38 shows a double row thrust needle hearing as it is applied to apropelling shaft in partial vertical sectional view.

Fig. 39 is a partial transverse sectional view of Fig. 38.

Fig. 40 shows the two sets of capillary interspaces in a thrust bearing.

Figs. 1 to 18 inclusive illustrate the application of the inventionfor-radial load and continuous rotation only.

Figs. 19 to 25 illustrate the application of the invention forreciprocating thrust bearings between parallel or concentricreciprocating members such as is used in high pressure and high speedhydraulic machines, compressors and rotary pumps.

Figs. 26 to 40 illustrate the application of the invention for rotary,continuous or reciprocating motion in axial thrust bearings such as inwater turbines, propeller shafts and for shafts under combined radialand axial load (Figs. 29,

30 and 31).

The substance of the invention is the same in all of the above mentionedillustrative embodiments and it is in the provision of improved resultsby so constructing the bearings that:

1. A specific bearing pressure as high as 7000 pounds per square inchmay be accommodated under all normal operation. Y

2. The maximum needle length will be below the capillary length whereincapillary length is the length of an oil column, which is maintained ina steel capillary tube against the gravitational force.

In order to accomplish the requirement under 1, for for instance in abearing like in Fig. 14 the 2 length of the needles is so determinedthat according to the designations of Figs. 12, 13, 14 and 15 the ratiobetween length and diameter is between a positive lower limit and apositive upper limit. Expressed in formula and in any linear scale-Furthermore in regard to load-carrying capacity the unit load on theworking bearing side as projected on the neutral bearing plane shall beabout '7000 pounds per square inch mathematically with abovedesignations:

' 1.D.lc=7000 lbs. per sq. in. 2

under all operating conditions, wherein it is a factor characterized bythe speed and is required for a maximum efficiency hearing. it is called.the load factor. For bearing materials known to me at the time offiling this application, the load factor It has the followingapproximate mean values at various speeds:

Speed in R. P. M. Load factor in pounds per sq. in.

4200 lbs. per sq. in. 2800 lbs. per sq. in. 2100 lbs. per sq. in.1400lbs.per sq. in. 3

Incomplete k 1-200 1: 200-1000 k 1000-5000 I:

II II II II In order to cut the friction between the individual needlesto the possible minimum it is essential will not and cannot maintaincapillary forced lubrication at all times and they will burn out andoverheat under load. It is Well known that 7 the combination of purelyhardened bearing members under sliding relative motion is inoperativefor the formation of oil film under the load carrying needles and isprohibitive due to the enormous line contact pressure. It is in thescope of this invention to eliminate overheating and seizure ofthe'bearings by the design of a positive length for the needles whichwill roll at the most favorable speed under the load and will drive theidle needles so that the entire needle assembly will have combinedrotary and individually rolling. motion. g

It is evident that in case of perfect rolling of the working needles,their rotary speed relative to the driving member (race) is exactly onehalf of the speed of the latter. Actually there is a slip between therolling needles and the races which increases the relative rotary speedof the needles as a whole. The rolling slip of the needles varies withthe speed and load of the bearings. At infinitely high speed and atsmall load the slip may become 100%.

Bearing structure With reference to the figures, i is a driving memberon which directly or indirectly a plurality of encircling needles 2 or 2are mounted to form a continuous bearing surface. A direct actingpassive member 3 and a direct acting active member Gare spaced by theneedles 2 and 2 respectively to maintain capillary interspaces 21 and 2ftherebetween. Members 3 and 6 or i and 3 form a circular capillary spaceopen at both ends as at H. The rounded end needles (see Figs. 12 and 13)are axially secured by plates t or by the shoulders of a driving memberI or V shoulders 3 of passive member 3. Active mem- Y bers 6 or passivemembers 3 are chamfei-ed as 2), to provide shoulders against the axialdisplacements of the needles in which case member 3 is provided withchamfers l0 and side clearance M for capillary lubrication. Member 3 isfurther provided with circular channels 9 (see Figure 3), to maintain acontacting oil supply for the capillary attraction of the bearinginterspaces. In

case the bearing load would require a needle length which would fallbeyond the above limits of capillary lubrication, its length would begreater than the ordinate l3 in Fig. 11, the needles are cut andarranged on double or triple rows as in Figs. 5 and 6, carefullyseparated by rings 8.

Fig. 9 shows a capillary tube ill with a capillary opening E8 in itwhich is holding fluid If! by capillary attraction. When the tube is setin vertical position and against gravity the fluid column i will notdrop out. The law of capillarity shown in Fig. 11 could be expressed ininches also, only the inch is not fit to express so conveniently thedimensions of a needle as the millimeter unit.

In case the active and passive bearing members in a machine cannot behardened on account of their material or size a complete bearing asshown in Fig. 14 is provided to mount it in a well known manner. Thecomplete bearing is provided with lubricating openings as at l and H andcircular grooves 9 to maintain lubricant in readiness.

It is very seldom possible to provide a submerged bearing because of thevery high speed. The passive bearing member must be drained'so l asudden over-heating will thin the oil film so that the bearing willbecome inoperative or permit only very low specific bearing load. Inorder to overcome failure in heavy load machinery, provisions are madesimilar to present illustrations.

In this case the needles are packed loosely with intervening capillaryclearance in a suitable retaining frame 22 to parallel the needles. Theretaining frame, however, isnot to be considered a cage such as used oncaged bearings as it does not engage the individual rollers to constrainthem to a fixed spaced relation in the direction of rotation. Thespacing of the individualrollers is effected by the capillary oil films,the only effect of the frame being to limit the total clearance in thedirection of rolling movement so that capillary films will be formedbetween the endcage for the rollers. Bearings using such a frame,

therefore, are also cageless. In such bearings very often there is aworking cycle when all the needles carry load by rolling and an idlecycle when the needles will only swim. In above illustrations themachine parts such as crossheads 6 and I6 and a rotor 3 form thecooperating bearing. Members 23, 24, 25 and 2B are parts of the rotatingcylinder and piston assembly.

Very often a radial load is combined with or accompanied by an axialload for which case the races 3 and 6 are formed conically such as shownin Fig. 29, with very slightly tapered needles such as in Figs. 26 and27 and 28. The performance of the tapered needles is the same as that ofthe cylindrical needles previously described.

The capillary interspaces are shown in Figs. 32 and 33 as at 21. Inmulti-row arrangement as in Fig. 31 the load can be doubled withoutincreasingthe length of the capillary needles 2. When the load is purelyaxial as in case of propeller shafts, large centrifugal pumps, turbinesand the like, the slightly tapered needle bearing forms an unprecedentedeasy solution of the remedy. If lubricant bath 33 fails and its level,

for any reason, drops below the needles. 2 it may run forconsiderablelength of time before damage occurs. The capillary fluidsupply entrapped by the needles will prevent that; even if bushing 35wears out and the bearing runs dry the circularrings 9 (Figure 36) willmaintain lubrication for considerable length of time.

Figs. 38 and 39 illustrate a propeller shaft 1 provided with thrustcollar l both faces of l are packed'with needles 2 to provide forwardand backward propulsion of the ship. Reaction members 6 are providedwith circular shoulders 6 to maintain circular rotation of the needles.

The needle bearing functions in a new way. In every bearing there is atotal clearance of at least the space of one needle. The inner race 6 inFig. 15 under the load assumes certain eccentricity in regard to theouter race 3. Therefore, it is evident that the needles at the smallerrace clearance side are the ones which carry the load. Let these needlesbe the ones which are shown in section in Fig. 15 and be called theworking needles. The working needles are rolling. The needles in thelarger clearance side of the bearing races are out of contact with theraces. The load action and the positive clearance, at least the space ofone needle, cause that clearance. Therefore the needles located in thelarger clearance half of the bearing which are unloaded and swimmingand, though freely rotatable, they do not roll appreciably while in thatparticular portion of the bearing. Instead they are impelled along thisportion of their path of travel by the loaded needles, the impellingforce being transmitted through the medium of the fluid films so thatthe swimming needles travel at the same circumferential speed as theloaded needles, that is, at one half the speed of the driving race. Theidle needles are then opposite to the working needles and consequentlyin Fig. 15 they are the needles which are shown inside elevation.

According to the spirit of the invention the working rollers are forcedto roll between races. They are sufiiciently loaded so that in theloaded zone they are forced to roll. However, when they are forced toroll individually the result is an absolute rotation of the entireneedle assembly at one half of the angular or rotary speed of thedriving race. Therefore, if the driving race rotates for example at 1000revolutions per minute the absolute revolutions of the needle assemblyas a whole will be 500 per minute only. In other words, speaking inrelative motion, the needlesin assembly will have 500 revolutions perminute relative to the inner and outer races or bearing members. Thereis thus formed by the needles a flexible sleeve-like bearing wherein thepath of the needles is not a perfect circle owing to the eccentricity ofthe passive and active bearing members.

If the needles would fit tightly between their races as theanti-friction bearing rollers do, then all the needles would be forcedto roll individually as the rollers of the anti-friction bearings withsubstantially rolling friction and heat development. If on the otherhand, the needles were too long so that individual rolling wereprevented by the braking effect of the needles themselves as it has beenproposed in the prior art, all the needles would slide in their entiretyand would have a speed substantially the same as the speed of thedriving member. According to, above example the needle bushing wouldslide with a relative velocity corresponding to 1,000 revolutions perminute. It is obvious that under load and with twice greater velocitythe friction and heat developed by the sliding motion will beconsiderably more. In addition to that the sliding friction under loadis ten times greater than the rolling friction under load. In fact, ifat sliding load transmission the lubrication fails, the hearing willseize whereas the rolling load transmission will operate perfectly inpresent invention where there is clearance for an air film between theneedles of relatively short length.

In fact bearings constructed according to the substance of thisinvention are capable of operating without any lubrication because theworking needles are rolling and the idle needles are revolving in unisonin a clearance space on air film. Therefore, these bearings may becalled oilless needle bearings". However, between the working needlesthe lubricant eliminates the fric- 10 tion due to the opposed directionof rotation of adjacent surfaces of the needles so that the re sultantfriction coeflicient in a rolling-sliding needle bearing flgures'0.004only.

' Various changes may be made in either of the 15 bearing structureshereinabove specifically described without departing from or sacrificingthe advantages of the invention as defined in the appended claims.

I claim: 1. An anti-friction bearing means comprising a pair ofrelatively movable bearing members, a plurality of elongated cagelessneedle rollers 02 circular cross section interposed between the membersfor transmitting loads from one member to the other, the axes of saidneedle rollers extending transversely of the direction of relativemovement of said members and being in rolling engagement with saidmembers under normal load conditions, said needle rollers beingvery-slightly 3 spaced from each other in the direction of movement ofthe members to provide capillary interspaces for retaining capillaryfilms of fluid between adjacent rollers, said films constraining the,needlerollers to said spaced relation with respect to each other as theneedle rollers roll on said members, whereby the needles may roll freelyabout their axes respectively substantially unrestrained by frictionalengagement with each other.

40 2. An anti-friction bearing means comprising a pair of relativelymovable bearing members, a plurality of elongated cageless needlerollers of circular cross section interposed between the members fortransmitting loads from one member 45 to the other, the axes of saidneedle rollers extending transversely of the direction of relativemovement of said'members and being in rolling engagement with saidmembers under normal load conditions, said needle rollers being very 50slightly spaced from each other in the direction of movement of themembers to provide capillary interspaces for retaining capillary filmsof fluid between adjacent rollers, and said needle rollers terminatingendwise in inwardly spaced relation to the transverse limits of saidmembers and having their ends free for providing spaces around the endsfor retaining capillary fluid films entirely enclosing each individualneedle roller, said capillary films constraining the needle 60 rollersto substantially equal spaced relation with respect to each other.

3. In an apparatus having relatively rotatable .inner and outercomplementary bearing members of circular cross section spaced radiallyfrom each mother, a plurality of elongated capillary cagemembers,whereby said rollers are unrestrained by adjacent rollers and aresubstantially freely rotatable about their respective axes.

4. In an apparatus having relatively rotatable inner and outercomplementary bearing mem bers of circular cross section spaced radiallyfrom each other, a plurality of elongated capillary cageless needlerollers interposed between said members for transmitting loads from onemember to the other and having their axes disposed transversely of thepath of relative rotation of the members, said rollers entirelysurrounding the inner bearing member with a total circumferentialclearance sufiicient to provide only capillary clearances between eachneedle roller and the needle rollers adjacent thereto.

5. In an apparatus having relatively rotatable inner and outercomplementary bearing members of circular cross section spaced radiallyfrom each other, a plurality of elongated capillary cageless needlerollers interposed between said members for transmitting loads from onemember to the other. and having their axes disposed transversely of thepath of relative rotation 01' the members, said rollers entirelysurrounding the inner bearing member with a total circumferentialclearance of from one to three roller diameters, and said needles beingfree from each other whereby capillary fluid films may form betweenadjacent needles and adjust said needles to positions substantiallyequally spaced from each other and constrain the needles to said spacedrelation.

6. In an apparatus having an inner bearing member and a complementaryouter bearing member forming relatively rotatable substantiallycylindrical bearing races, a plurality of capillary needle rollersinterposed between said races in load transmitting relationship, saidrollers being spaced apart from each other circumferentially of theraces a capillary distance for retaining capillary fluid filmstherebetween, said films constraining the rollers to said spacedrelation whereby each needle may roll freely substantially unrestrainedby adjacent needles, and. said races, when under load, having radialspacing at the instantaneous unloaded portion providing radial clearancebetween the races and the needle rollers to permit free revolution ofthe unloaded rollers by the loaded rollers, circumferentially of theraces by force transmitted through the medium of the capillary films,whereby all the loaded rollers may roll freely under normal loads andthe unloaded rollers, although free to roll, may be moved, substantiallyfree from rotation about their respective axes, in the same direction.

'7. In an apparatus having an inner bearing member and a complementaryouter bearing member forming relatively rotatable substantiallycylindrical bearing races, a plurality of capillary needle rollersinterposed between said races in load transmitting relationship, saidrollers being spaced apart from each other circumferentially of theracesa capillary distance for retaining capillary fluid filmstherebetween, said films constraining the rollers to said spacedrelation whereby each needle may roll freely substantially unrestrainedby adjacent needles, and said races having radial spacing at theinstantaneous unloaded portion providing capillary radial clearancebetween the races and the needle rollers to permit free travel of theunloaded rollers by the loaded rollers, circumferentially of the racesby force transmitted through the medium of the capillary films, wherebyall the loaded rollers may roll freely under normal loads and theunloaded rollers, although free to roll, may be moved, substantiallyfree from rotation about their respective axes, in the same direction.

8. A bearing means comprising a pair of complementary spaced relativelymovable races, a plurality of cageless capillary needle rollers in 10load transmitting relation therebetween, said needle rollers extendingtransversely of the direction of relative movement of the races, andhaving a total clearance in the direction of relative movement of theraces sufiicient to provide capillary fluid interspaces between eachroller and adjacent rollers, for formation of a capillary fluid cage toconstrain the rollers to spaced relation from each other.

9. A hearing means comprising a pairof complementary spaced relativelymovable races, a plurality of cageless capillary needle rollers in loadtransmitting relation therebetween, said needle rollers extendingtransversely of the direction of relative movement of the races, andhaving a total clearance in the direction of relative movement of theraces sufficient to provide capillary fluid interspaces between eachroller and adjacent rollers, for formation of a capillary fluid .cage toconstrain the rollers to spaced relation from each other, and saidrollers terminating short of the transverse limits of the races andbeing movable axially therebetween while yieldably constrained toposition by the capillary fluid film.

10. A bearing means comprising spaced complementary bearing membersmovable with respect to each other, capillary cageless needle rollersinterposed between the members in load transmitting relation, saidrollers having capil- 40 lary fluid clearance spaces therebetween in thedirection of movement of the bearing members,

' for retaining fluid by capillarity between the rollers, the ratio ofthe length to the diameter of the rollers being between the limitsl/diameter is equal to or greater than 5 and is equal to or less than10.

11. A bearing means comprising spaced complementary bearing membersmovable with respect to each other, a plurality of capillary needlerollers interposed between said members in load transmittingrelationship, said rollers having their axes extending transversely ofthe direction of relative movement of the members and being'spaced fromeach other in the direction of movement to form capillary fluidinterspaces therebetween, and the length of each roller being sufiicientto permit formation of fluid A films by capillarity for the full lengththereof.

12. A bearing means comprising relatively movable complementary bearingmembers, a. plurality of sets of capillary needle rollers interposedbetween said members in. load transmitting relationship, said rollershaving their axes extending transversely of the direction of movement ofthe members and said rollers being spaced form each other in thedirection of movement to form capillary fluid interspaces therebetween,the length of each roller being suflicient to permit formation of fluidfilms by capillarity for the full length of the roller, the rollers ofeach set being limited to said capillary lengths and said sets beingspaced apart transversely of the direction of relative movement of thebearing members, and means for admitting fluid to the sets of rollers atpoints between the sets. I

13. An anti-friction bearing means comprising a pair of relativelyreciprocable bearing members, a plurality of elongated cageless needlerollers of circular cross section interposed between the members fortransmitting loads from one member to the other, the axes of said needlerollers extending transversely of the direction of relative movement ofsaid members and being in rolling engagement with said members undernormal load conditions, said needle rollers being very slightly spacedfrom each other in the direction of movement of the members to providecapillary interspaces for retaining capillary films of fluid betweenadjacent rollers said films constraining the needle rollers to saidspaced relation with respect to each other, as the needle rollers rollon said members, whereby the needles may roll freely about their axesrespectively substantially unrestrained by frictional engagement witheach other.

14. A bearing means comprising a pair of complementary spaced relativelyreciprocable members, a plurality of cageless capillary needle rollersin load transmitting relation therebetween, said needle rollersextending transversely of the direction of relative movement of saidreciprocable members, and having a total clearance in the direction ofrelative movement of said members sufl'icient to provide capillary fluidinterspaces between each roller and adjacent rollers,

for formation of a capillary fluid cage to constrain the rollers tospaced relation from each other.

15. An anti-friction bearing means comprising a pair of relativelyrotatable bearing members, a plurality of elongated cageless taperedneedle rollers of circular cross section interposed between the membersfor transmitting loads from one member to the other, the axes of saidneedle rollers extending transversely of the direction of relativemovement of said members and. being in rolling engagement with saidmembers under normal load conditions, said needle rollers being veryslightly spaced from each other in the direction of movement of themembers to provide capillary interspaces for retaining capillary filmsof fluid between adjacent rollers, said films constraining the needlerollers to said spaced relation with respect to each other as the needlerollers roll on said members, where by the needles may roll freely abouttheir axes respectively substantially unrestrained by frictionalengagement with each other.

16. A bearing means comprising a pair of complementary spaced relativelyrotatable races, a plurality of cageless capillary tapered needlerollers in load transmitting relation therebetween, said needle rollersextending transversely of the direction of relative movement of theraces, and having a total clearance in the direction of relativemovement of the races sufficient to provide capillary fluid interspacesbetween each roller and adjacent rollers, for formation of a capillaryfluid cage to constrain the rollers to spaced relation from each other.

ELEK BENEDEK.

